An enzymatic process for the preparation of cephalosporins by condensation of an amino acid derivative and a 7-amino cephalosporin nucleus is described in U.S. Pat. No. 3,816,253. In U.S. patent application Ser. No. 07/874,257 filed Apr. 24, 1992, now abandoned, an improved enzymatic process for preparing cephalosporins is disclosed, particularly relating to condensing the corresponding 7-amino cephalosporin nucleus with an amino acid. Heretofore, after such enzymatic acylation reaction, the compound of interest, cefaclor, is in a complex environment which contains not only the nucleus but also phenylglycine, D-phenylglycinemethyl ester, and salts thereof. In light of the complexity of this mixture, the cefaclor has been isolated by a series of columns. Of course, this results in loss of product and is also time consuming.
In view of the above, what is needed in the art is a process for selectively removing the cefaclor from the complex acylation reaction mixture.